Biology (A) 9BN0/01 May June 2020

Edexcel A Level Biology A (9BN0) Jun 2020

معلم موافق رایگان بودن است.

1. Protein Synthesis and Enzyme Folding: Role of ribosomes in protein synthesis, impact of misfolded enzymes in disease, and extracellular enzyme secretion pathways.

2. Climate Change and Ecosystem Impact: Effects on golden snub-nosed monkey populations, reduction in seed availability, and use of dendrochronology and ice cores as evidence.

3. Microbiology and Immune Defense: Physical and chemical barriers against pathogens, gut microbiome competition against harmful bacteria, and low bacterial diversity in the stomach due to acidity.

4. Genetic Mutations and Disease: Effect of base substitution on haemoglobin function, impact of pre-mRNA modification on protein variety, and RNA transcription processing.

5. Reproduction and Environmental Factors: Acrosome function in fertilization, effects of polychlorinated biphenyls (PCBs) on sperm motility, and mitochondrial role in energy production.

6. Ecological Succession and Biodiversity: Tree species abundance changes over 200 years post-glacier retreat, nitrogen fixation in pioneer species, and soil condition effects on plant diversity.